City raced into a three-goal lead inside 24 minutes thanks to strikes from Ilkay Gundogan, Bernardo Silva and Sergio Aguero.

Gundogan scored again after half-time to put City in a commanding position ahead of the return leg at the Etihad on March 7.

"The Champions League is 180 minutes, but we are almost there," said City boss Guardiola. "I'm not saying it's done, because in football anything can happen, but it's an amazing result.

"We could have been 2-0 down but then we were 0-2 up. We were clinical and I am delighted with the performance.

Sergio Aguero (L) is congratulated by Kevin De Bruyne after putting City 3-0 ahead

"We kept our level, we fought hard and created chances to score. They were four amazing goals. Overall I'm delighted."

Guardiola also paid tribute to Gundogan, who might even have claimed a hat-trick had Tomas Vaclik not saved from him in the closing stages.

"He's a guy with special qualities," said Guardiola. "He's amazing with a good sense of the goal.

"When I see him play I realise how we missed him last season. He is a special player with a lot of personality. He doesn't feel pressure, he's a top player."

Ilkay Gundogan scored his second and City's fourth of the night with a stunning strike

The emphatic nature of the victory means Guardiola may be able to rest players in the second leg but he is not looking that far ahead yet.

First City face Wigan in the FA Cup and Arsenal in the Carabao Cup final, with tricky league games against the Gunners and Chelsea also coming before the Basel return fixture.

Guardiola said: "That's so important but we have to be focused and it's after Chelsea. It's so important to focus on them and take another step in the Premier League.

Guardiola congratulates Aguero after City's emphatic win in Basel

"Vinny (Kompany) is back, Fabian (Delph) is back - a lot of players have come back from long-term injuries. That's good for everyone and (Gabriel) Jesus and (Benjamin) Mendy are coming back. We'll have almost the whole squad for this period when we will need everyone involved."

Basel coach Raphael Wicky admitted his side were outplayed by a ruthless City side.

Wicky said: "They were very clinical, scoring three goals in the first half. We started well, we created chances and managed to win balls but, as I said yesterday, we needed a perfect night. We needed to take the opportunities and be clinical. But we conceded goals too easily and after we went 3-0 down I think the game was decided."